Cerium dioxide nanoparticles (CeO2 NPs) are an engineered nanomaterial that possesses unique catalytic, oxidative and reductive properties. Currently, CeO2 NPs are being used as a fuel catalyst but these properties are also utilized in the development of potential drug treatments for radiation and stroke protection. These uses of CeO2 NPs present a risk for human exposure; however, to date no studies have investigated the effects of CeO2 NPs on the microcirculation following pulmonary exposure. Previous studies in our laboratory with other nanomaterials have shown impairments in normal microvascular function after pulmonary exposures. Therefore, we predicted that CeO2 NP exposure would cause microvascular dysfunction that is dependent on the tissue bed and dose. Twenty-four hour post exposure to CeO2 NPs (0–400 μg), mesenteric and coronary arterioles were isolated and microvascular function was assessed. Our results provided evidence that pulmonary CeO2 NP exposure impairs endothelium-dependent and -independent arteriolar dilation in a dose-dependent manner. The CeO2 NP exposure dose which causes a 50% impairment in arteriolar function (EC50) was calculated and ranged from 15 – 100 μg depending on the chemical agonist and microvascular bed. Microvascular assessments with acetylcholine revealed a 33–75% reduction in function following exposure. Additionally, there was a greater sensitivity to CeO2 NP exposure in the mesenteric microvasculature due to the 40% decrease in the calculated EC50 compared to the coronary microvasculature EC50. CeO2 NP exposure increased mean arterial pressure in some groups. Taken together these observed microvascular changes may likely have detrimental effects on local blood flow regulation and contribute to cardiovascular dysfunction associated with particle exposure.

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Heteroleptic bis(tert-butylimido)bis(N,N'-diisopropylacetamidinato) compounds of molybdenum and tungsten are introduced as precursors for atomic layer deposition (ALD) of tungsten and molybdenum oxide thin films using ozone as the oxygen source. Both precursors have similar thermal properties, but exhibit different growth behavior. With the molybdenum precursor, high growth rates up to 2 Å/cycle at 300 °C and extremely uniform films are obtained, although the surface reactions are not completely saturative. The corresponding tungsten precursor enables saturative film growth with a lower growth rate of 0.45 Å/cycle at 300 °C. Highly pure films of both metal oxides are deposited and their phase as well as stoichiometry can be tuned by changing the deposition conditions. The WOx films crystallize as -WO3 at 300 °C and above while the films deposited at lower temperatures are amorphous. Molybdenum oxide can be deposited as either amorphous ( 250 °C), crystalline suboxide (275 °C), a mixture of suboxide and α-MoO3 (300 °C), or pure α-MoO3 films ( 325 °C). MoOx films are further characterized by synchrotron photoemission spectroscopy and temperaturedependent resistivity measurements. A suboxide MoOx film deposited at 275 °C is demonstrated to serve as an efficient hydrogen gas sensor at a low operating temperature of 120 °C.

A bottom-up process from precursor development for tin to plasma-enhanced atomic layer deposition (PEALD) for tin­(IV) oxide and its successful implementation in a working thin-film transistor device is reported. PEALD of tin­(IV) oxide thin films at low temperatures down to 60 °C employing tetrakis-(dimethylamino)­propyl tin­(IV) [Sn(DMP)4] and oxygen plasma is demonstrated. The liquid precursor has been synthesized and thoroughly characterized with thermogravimetric analyses, revealing sufficient volatility and long-term thermal stability. [Sn­(DMP)4] demonstrates typical saturation behavior and constant growth rates of 0.27 or 0.42 Å cycle–1 at 150 and 60 °C, respectively, in PEALD experiments. Within the ALD regime, the films are smooth, uniform, and of high purity. On the basis of these promising features, the PEALD process was optimized wherein a 6 nm thick tin oxide channel material layer deposited at 60 °C was applied in bottom-contact bottom-gate thin-film transistors, showing a remarkable on/off ratio of 107 and field-effect mobility of μFE ≈ 12 cm2 V–1 s–1 for the as-deposited thin films deposited at such low temperatures.

a b s t r a c tThere is an increasing desire to control and monitor gas emissions from coal-fired power plants and other industrial systems. With this desire, there is a growing need for distributed gas sensors to monitor these emissions at high temperature ( > 600 • C), especially for pollutants such as SO 2 and H 2 S. The objective of this work was to investigate molybdenum and tungsten binary and ternary oxide thick films on a chemiresistive sensor platform for monitoring of gas sulfur species. The work evaluated the SO 2 sensitivity of WO 3 , MoO 3 , SrMoO 4 , NiMoO 4 , Sr 2 MgMoO 6-␦ (SMM), Sr 2 MgWO 6-␦ (SMW), NiWO 4 , and SrWO 4 compositions at 600-1000 • C. The SrMoO 4 composition at both the micro-and nano-particulate scale showed the most promise in sensitivity, stability and selectivity to SO 2 up to 1000 • C. Hydrothermallysynthesized nano-SrMoO 4 showed the highest sensor response with the R max values of −17.2, −50.2 and −40.5 upon exposure to a 20 min pulse of 2000 ppm of SO 2 at 600 • C, 800 • C and 1000 • C, respectively. Similar sensitivity trends were distinguished down to 1-5 min SO 2 pulses. The nano-SrMoO 4 showed low cross-selectivity to H 2 and CO. Finally, the nano-SrMoO 4 sensor was also tested with H 2 and coal syngas containing 5-100 ppm H 2 S, where high sensitivities were realized for both, but the sensing mechanism was altered in the latter (n-type to p-type semiconducting behavior). In order to better understand the sensing mechanism, extensive microstructural, electronic and chemical property characterizations were completed in this work.